Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UVa scientists detail salmonella protein

26.09.2003


A protein in Salmonella bacteria called SipA invades healthy human cells by using two arms in a "stapling" action, according to scientists at the University of Virginia Health System. The U.Va. researchers, working with colleagues at Rockefeller University in New York, report their findings in the September 26 edition of the magazine Science.


Edward Egelman, professor of biochemistry and molecular genetics at U.Va., said the significance of this research is that it could be possible to design molecules to prevent SipA from binding to a protein called actin, preventing the severe infection associated with Salmonella.

According to the Centers for Disease Control and Prevention, various types of the Salmonella bacteria are responsible for up to four million infections and 500 deaths in the United States every year. Salmonella can cause diarrhea, fever and abdominal cramps. Most people recover without treatment, but young children, the elderly and people with compromised immune systems are at risk for developing severe infections. There is no vaccine to prevent Salmonella-related sickness.

Egelman and his colleagues found that SipA works as a molecular "staple" and tethers itself to actin, a protein found in all human cells. SipA can polymerize actin into long filaments.



This activity may explain how this bacterial protein helps rearrange a cell’s cytoskeleton, or the inner scaffold that gives a cell shape and provides motility. By remodeling the cytoskeleton of host cells, bacterial proteins such as SipA allow the Salmonella bacteria to infect these cells.

"This is a cunning evolutionary pathway that has developed with Salmonella," Egelman said. "It has the interesting property of being able to control the host actin filaments by using arms to do it. It has actually evolved, we believe, to mimic human proteins that bind to actin. This allows Salmonella to become a Trojan horse of sorts, causing healthy cells to engulf the Salmonella bacteria."

Research teams at U.Va. and Rockefeller University used an electron microscope, x-ray crystallography and 3-D reconstruction to image the SipA protein. They found that the molecule is unexpectedly compact, heart shaped, with a globular core, flexible polypeptide extensions and a large patch that may help SipA bind to the mostly acidic surface of actin.

Bob Beard | EurekAlert!
Further information:
http://hsc.virginia.edu/news
http://www.sciencemag.org

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>